Bulletin of the World Health Organization

Maternal body mass index and gestational weight gain and their association with perinatal outcomes in Viet Nam

Erika Ota, Megumi Haruna, Motoi Suzuki, Dang Duc Anh, Le Huu Tho, Nguyen Thi Thanh Tam, Vu Dinh Thiem, Nguyen Thi Hien Anh, Mitsuhiro Isozaki, Kenji Shibuya, Koya Ariyoshi, Sachiyo Murashima, Hiroyuki Moriuchi & Hideki Yanai

Volume 89, Number 2, February 2011, 127-136

Table 3. Ratio of the odds of delivering an infant too large for gestational age relative to the odds of delivering an infant with appropriate size for gestational age as a function of maternal characteristics, infant sex and gestational age at delivery, Nha Trang, Viet Nam, 2007–2008

Characteristic No.a/totalb (%) Crude OR 95% CI P Adjusted OR 95% CI P
Gestational weight gain (kg)
< 10 47/625 (7.5) 0.65 0.46–0.92 0.014 0.72 0.50–1.02 0.067
≥ 10 but < 15 139/1383 (10.1) 1.00 1.00
≥ 15 109/618 (17.6) 1.97 1.51–2.59 < 0.001 1.93 1.46–2.57 < 0.001
BMIc
Low 37/638 (5.8) 0.43 0.30–0.61 < 0.001 0.51 0.35–0.74 < 0.001
Normal 205/1758 (11.7) 1.00 1.00
High 53/230 (23.0) 2.25 1.61–3.15 < 0.001 2.04 1.43–2.91 < 0.001
Maternal age (years)
< 24 39/715 (5.5) 0.47 0.32–0.69 < 0.001 0.64 0.43–0.96 0.030
25–29 103/943 (10.9) 1.00 1.00
30–34 105/625 (16.8) 1.65 1.23–2.21 0.001 1.24 0.91–1.70 0.175
≥ 35 48/343 (14.0) 1.33 0.92–1.92 0.131 0.98 0.66–1.44 0.916
Parity
Primipara 95/1291 (7.4) 1.00 1.00
Multipara 200/1335 (15.0) 2.22 1.72–2.87 < 0.001 1.93 1.43–2.61 < 0.001
Income ( × 1 000 Vietnamese dong)
< 1 500 17/223 (7.6) 0.75 0.44–1.28 0.288 0.93 0.53–1.62 0.789
≥ 1 500 but < 2 500 92/924 (10.0) 1.00 1.00
≥ 2 500 but < 3 500 94/776 (12.1) 1.25 0.92–1.69 0.157 1.15 0.83–1.59 0.391
≥ 3 500 92/703 (13.1) 1.36 1.00–1.85 0.049 1.13 0.79–1.61 0.507
Education (years)
< 12 137/1400 (9.8) 0.82 0.61–1.09 0.167 0.79 0.58–1.09 0.791
12 83/707 (11.7) 1.00 1.00
> 12 75/519 (14.5) 1.27 0.91–1.78 0.162 1.20 0.83–1.72 1.197
Total physical activityd in MET h/wk
< 25th percentile 68/641 (10.6) 1.01 0.71–1.44 0.954 1.17 0.81–1.71 0.400
≥ 25th but < 50th percentile 68/646 (10.5) 1.00 1.00
≥ 50th but < 75th percentile 82/669 (12.3) 1.19 0.85–1.67 0.319 1.09 0.76–1.56 0.658
≥ 75th percentile 77/669 (11.5) 1.11 0.78–1.57 0.563 0.90 0.63–1.30 0.587
Smoking exposure
None 198/1720 (11.5) 1.00 1.00
Passive indoor smoking 97/906 (10.7) 0.92 0.71–1.19 0.535 1.08 0.82–1.42 0.576
Infant sex (male = 1, female = 0) 171/1383 (12.4) 1.27 1.00–1.63 0.053 1.22 0.95–1.58 0.120
Gestational age at delivery 1.01e 0.91–1.13 0.797 1.00 0.89–1.12 0.964

BMI, body mass index; CI, confidence interval; MET h/wk, metabolic equivalent hours per week; OR, odds ratio.

a This represents the number of infants too large for gestational age (n = 295) born to women with the characteristic.

b This represents the number of infants of appropriate size plus the number of infants too large for gestational age (n = 2626) born to women with the characteristic.

c BMI represents body weight in kilograms divided by body surface area in square metres. Categories: low BMI: < 18.5; normal BMI, ≥ 18.5 but < 23.0; high BMI, ≥ 23.0.

d There is one case with missing data for physical activity.

e This OR represents the change in the risk of delivering a large baby with each additional week of gestation.